87840251 has 2 divisors, whose sum is σ = 87840252. Its totient is φ = 87840250.

The previous prime is 87840209. The next prime is 87840281. The reversal of 87840251 is 15204878.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 87840251 - 2⁶ = 87840187 is a prime.

It is a super-3 number, since 3×87840251³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87840281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43920125 + 43920126.

It is an arithmetic number, because the mean of its divisors is an integer number (43920126).

Almost surely, 2^87840251 is an apocalyptic number.

87840251 is a deficient number, since it is larger than the sum of its proper divisors (1).

87840251 is an equidigital number, since it uses as much as digits as its factorization.

87840251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 87840251 is about 9372.3130016021. The cubic root of 87840251 is about 444.5267046327.

The spelling of 87840251 in words is "eighty-seven million, eight hundred forty thousand, two hundred fifty-one".